Made in USA, with class-leading engagement and a unique sound.

• 0.52 degree engagement, 690 POE
• Unique high-pitched sound

We score them a 8/10 in loudness, with a unique sound. 

Please note that some customers have had reliability issues with their Hydras. I9 has moved to address this with an updated axle. We recommend Project 321 G3 hubs as a more robust, high-engagement product for a worry-free ownership experience. 

You can read more at the manufacturer’s website: https://industrynine.com/hubs/mountain/hydra-classic-boost-6b-rear/

Weight
Front : 176 grams
Rear : 301 grams

Reliable, excellent strength-to-weight ratio, and perfectly round from the factory. 

Setting the MTB alloy rim benchmark for the last five years.

FR541 - A must for gravity riders hard on their wheels, and e-bikes with the extra mass. All additional weight is in the flange for improved dent resistance.

XM481 - For Trail and All-Mountain wheelsets, and strong enough on the front of an Enduro bike. 

XR391 - Top of the line XC alloy rim with 25mm internal width to suit modern XC tyres.

GR531 - Made for Gravel riders, these rims sport a 24mm internal width to support modern gravel tyres

We don’t offer the EX511 as it’s just 10 grams lighter than the FR541 and materially weaker. Please contact us if you really want this rim. 

Alpina Raggi Spokes and Nipples

The highest quality spoke and nipples, made in Italy since 1926.

Alpina is famous for its automation, which ensures consistency and quality whilst manufacturing wheel components. Alpina Nyloc nipples are particularly innovative, with a high 12Nm of locking force consistent throughout the lifetime of the nipple, no matter how many times they are adjusted. All Alpina spokes are guaranteed to be made from the highest quality European wire, unlike some of its closest competitors.

The Alpina Lite spoke is a double butted round spoke directly equivalent to the DT Swiss Competition.

The Alpina Ultralite Aero spoke is a bladed spoke directly equivalent to a DT Swiss AeroLite. Swapping to the Ultralite Aero spoke saves approximately 100g on your wheelset.